Field of the Disclosure
The present disclosure relates generally to processor systems and, more particularly, to three-dimensional processor stacks.
Description of the Related Art
Conventional processing systems are based on two-dimensional (2-D) structures such as a system-on-a-chip (SoC), which may include a variety of components of different sizes and processing capabilities. For example, a heterogeneous SoC may include a combination of processor cores such as one or more central processing units (CPUs), one or more graphics processing units (GPUs), or one or more specialized hardware accelerator processors. A higher level of integration can be achieved by implementing the processing system as a three-dimensional (3-D) structure formed by stacking and interconnecting multiple silicon layers that each include one or more processor cores. The stacked silicon layers in the 3-D processor stack are separated by distances of tens to hundreds of microns and exhibit a high degree of thermal coupling. Thus, heat generated in one or more processor cores of one silicon layer can raise the temperature of the processor cores in the other silicon layers in the 3-D processor stack.